Project details

Due to significant investment by our client Brett Aggregates in the form of new unloading equipment at the Eastern Quay of Ridham Sea Terminal, a decision was taken to strengthen an existing gravity wall. This involved the construction of a 100m long sheet piled wall immediately behind the gravity wall, tied to a sheet piled anchor wall located further inland. The existing gravity wall has been connected to the front sheet piled wall using tie bars. This will reduce any movement induced on the structure, and avoid any potential instability.

To stabilise the existing Gravity Wall, tie bars have been installed through the structure and connected to the front sheet piled wall.

Initial works including scanning the line of the sheet piled wall immediately adjacent to the existing gravity structure, allowing the identification of services. The pile line was then excavated to remove any obstructions. Using a traditional piling gate, the 16m long AZ52 sheet piles were lifted into position and driven to refusal using a vibro and drop hammer. The same process was used when installing the rear sheet piled wall.

A scaffolding system was erected across the front of the gravity wall, providing access to install the tie bars to connect the structure with the new sheet piled wall. Across a series of identified positions, holes were core drilled into the gravity wall to incorporate the tie bars and associated ducting. The 6m long tie bars were then lifted into position and secured using a wailing beam complete with fixings. Following grouting, the tie bars were tensioned at both ends.

To enable the installation of tie bars between the two newly installed sheet piled structures, an existing concrete deck slab was first broken out, prior to excavation to the required ground level. Following coring of the sheet piles, wailing beams were secured in position, allowing for the installation of the tie bars.

Further works included the construction of a new RC deck slab and crack repairs across the existing gravity wall.

Given the need to complete the project in advance of the installation of unloading equipment, the programme was accelerated, which involved working 7 days a week. Throughout construction, the adjacent quayside terminal remained fully operational.